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1.
Malaivijitnond S Lekprayoon C Tandavanittj N Panha S Cheewatham C Hamada Y 《American journal of primatology》2007,69(2):227-233
In January and March of 2005, we conducted surveys of long-tailed macaques at Piak Nam Yai Island, Laem Son National Park (9 degrees N 34-35', 98 degrees E 28'), Ranong Province, situated in southern Thailand. Two of the three troops of long-tailed macaques found on the island were observed using axe-shaped stones to crack rock oysters, detached gastropods (Thais tissoti, Petit, 1852), bivalves (Gafrarium divaricatum, Gmelin, 1791), and swimming crabs (Thalamita danae, Stimpson, 1858). They smashed the shells with stones that were held in either the left or right hand, while using the opposite hand to gather the oyster meat. Some monkeys used both hands to handle the stones. According to Matsuzawa's 1996 hierarchical classification of tool usage (levels 0-3), the tool usage by Thai long-tailed macaques could be characterized as either level 1 (cracking rock oysters with stones) or level 2 (cracking drifting mollusks and crabs with stones by placing them on a rock). Our discovery of stone-tool usage by Thai long-tailed macaques provides a new point of reference for discussions regarding the evolution of tool usage and the material culture of primates. 相似文献
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Fragaszy D Izar P Visalberghi E Ottoni EB de Oliveira MG 《American journal of primatology》2004,64(4):359-366
We conducted an exploratory investigation in an area where nut-cracking by wild capuchin monkeys is common knowledge among local residents. In addition to observing male and female capuchin monkeys using stones to pound open nuts on stone "anvils," we surveyed the surrounding area and found physical evidence that monkeys cracked nuts on rock outcrops, boulders, and logs (collectively termed anvils). Anvils, which were identified by numerous shallow depressions on the upper surface, the presence of palm shells and debris, and the presence of loose stones of an appropriate size to pound nuts, were present even on the tops of mesas. The stones used to crack nuts can weigh >1 kg, and are remarkably heavy for monkeys that weigh <4 kg. The abundance of shell remains and depressions in the anvil surface at numerous anvil sites indicate that nut-cracking activity is common and long-enduring. Many of the stones found on anvils (presumably used to pound nuts) are river pebbles that are not present in the local area we surveyed (except on or near the anvils); therefore, we surmise that they were transported to the anvil sites. Ecologically and behaviorally, nut-cracking by capuchins appears to have strong parallels to nut-cracking by wild chimpanzees. The presence of abundant anvil sites, limited alternative food resources, abundance of palms, and the habit of the palms in this region to produce fruit at ground level all likely contribute to the monkeys' routine exploitation of palm nuts via cracking them with stones. This discovery provides a new reference point for discussions regarding the evolution of tool use and material culture in primates. Routine tool use to exploit keystone food resources is not restricted to living great apes and ancestral hominids. 相似文献
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术中应用胆道镜治疗胆道疾病64例,使残余结石发生率由11%下降至2%左右,认为纤维胆道镜对明确诊断减少残余结石的发生有重要价值。 相似文献
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We investigated sex differences in how Burmese long-tailed macaques (Macaca fascicularis aurea) used stone tools to open shelled food items along the shores of two islands in Laemson National Park, Thailand. Over a 2-week period in December 2009, we collected scan and focal samples on macaques when they were visible along the shores and mangroves. We found females used stones more often while feeding and used smaller tools than males. Females also processed sessile oysters more than males, whereas males processed unattached foods more than females. It was unclear which sex was overall more proficient at stone tool use, but males did perform significantly better at opening unattached food items with large pounding stones. Females also struck food items more times during tool-use bouts and at a faster rate, but no significant difference was found in average tool-use bout duration. Males processed foods slightly faster within a tool-use bout, but we were unable to detect a significant difference in the rate of food processing while foraging with tools. In summary females chipped open sessile oysters with an axing technique more than males, while males used larger stones to pound open unattached shelled food more often than females. Despite using pounding more than females, males also regularly utilized the axing technique on sessile oysters. Our results are the first assessment of sex differences in macaque stone tool use, providing a basis for comparison with tool use in other primates, and to nonfunctional forms of stone use in other macaques. 相似文献
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A tale of North and South America: time and mode of dispersal of the amphitropical genus Munroa (Poaceae,Chloridoideae)
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Leonardo D. Amarilla Jorge O. Chiapella Victoria Sosa Natalia C. Moreno Ana M. Anton 《Botanical journal of the Linnean Society. Linnean Society of London》2015,179(1):110-125
Plant disjunctions have provided some of the most intriguing distribution patterns historically addressed by biogeographers. We evaluated the three hypotheses that have been postulated to explain these patterns [vicariance, stepping‐stone dispersal and long‐distance dispersal (LDD)] using Munroa, an American genus of grasses with six species and a disjunct distribution between the desert regions of North and South America. The ages of clades, cytology, ancestral characters and areas of distribution were investigated in order to establish relationships among species, to determine the time of divergence of the genus and its main lineages, and to understand further the biogeographical and evolutionary history of this genus. Bayesian inference recovered the North American M. pulchella as sister species to the rest. Molecular dating and ancestral area analyses suggest that Munroa originated in North America in the late Miocene–Pliocene (7.2 Mya; 8.2–6.5 Mya). Based on these results, we postulate that two dispersal events modelled the current distribution patterns of Munroa: the first from North to South America (7.2 Mya; 8.2–6.5 Mya) and the second (1.8 Mya; 2–0.8 Mya) from South to North America. Arid conditions of the late Miocene–Pliocene in the Neogene and Quaternary climatic oscillations in North America and South America were probably advantageous for the establishment of populations of Munroa. We did not find any relationship between ploidy and dispersal events, and our ancestral character analyses suggest that shifts associated with dispersal and seedling establishment, such as habit, reproductive system, disarticulation of rachilla, and shape and texture of the glume, have been important in these species reaching new areas. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 110–125. 相似文献
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The lack of mesocoelomic pores and the existence of a stone canal connecting proto-and mesocoel are characteristic peculiarities of echinoderms in contrast with the situation in other trimeric archicoelomates. The ultrastructure of the stone canal has been studied in order to understand its function in the strategically important position between two coelomic spaces with different functions. The epithelium of the Eucidaris (Echinoidea) stone canal is composed of three cell types: (1) ciliated cells, (2) cells with long basal processes containing myofilaments, and (3) granulated cells, which may represent secretory neurons. Nerve fibres of two types are common in the epithelium. We consider the stone canal to be a structure controlling fluid transport; its wall may exert peristaltic movements or tonic contractions and dilations which are under control of the nervous system. The ciliated cells additionally may have phagocytotic capacities. Similarities with the fine structure of the wall of the mesocoelomic pores in the pterobranch Cephalodiscus are discussed. 相似文献
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Four new compounds, stigmastanol-3beta-p-glyceroxydihydrocoumaroate (1), stigmastanol-3beta-p-butanoxydihydrocoumaroate (2), lanast-7,9(11)-dien-3alpha,15alpha-diol-3alpha-D-glucofuranoside (3) and 1-phenyl-2-hydroxy-3,7-dimethyl-11-aldehydic-tetradecane-2-beta-D-glucopyranoside (4), along with several known compounds were isolated from the methanol extract of hulls of Oryza sativa. The new structures were established by one- and two-dimensional NMR and in combination with IR, EI/MS, FAB/MS and HR-FAB/ MS. Compound (3) strongly inhibited the growth of duckweed (Lemna paucicostata Hegelm 381), whilst compounds (2) and (4) exhibited weak inhibition. 相似文献
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Michael D. Gumert Marius Kluck Suchinda Malaivijitnond 《American journal of primatology》2009,71(7):594-608
Stone hammering in natural conditions has been extensively investigated in chimpanzees and bearded capuchins. In contrast, knowledge of stone tool use in wild Old World monkeys has been limited to anecdotal reports, despite having known for over 120 years that Macaca fascicularis aurea use stone tools to process shelled foods from intertidal zones on islands in the Andaman Sea. Our report is the first scientific investigation to look at the stone tools used by these macaques. We observed they were skilled tool users and used stone tools daily. They selected tools with differing qualities for differing food items, and appeared to use at least two types of stone tools. Pounding hammers were used to crush shellfish and nuts on anvils and axe hammers were used to pick or chip at oysters attached to boulders or trees. We found significant physical differences between these two tools. Tools at oyster beds were smaller and exhibited scarring patterns focused more often on the points, whereas tools found at anvils were larger and showed more scarring on the broader surfaces. We also observed grip differences between the two tool types. Lastly, macaques struck targets with axe hammers more rapidly and over a wider range of motion than with pounding hammers. Both our behavioral and lithic data support that axe hammers might be used with greater control and precision than pounding hammers. Hand‐sized axe hammers were used for controlled chipping to crack attached oysters, and larger pounding hammers were used to crush nuts and unattached shellfish on anvils. In addition to stones, they also used hand‐sized auger shells (Turritella attenuata) as picks to axe attached oysters. Pound hammering appears similar to the stone tools used by chimpanzees and capuchins, but axe hammering has not yet been documented in other nonhuman primates in natural conditions. Am. J. Primatol. 71:594–608, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
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The colonisation of ornamental marble statues in theBoboli Gardens of Florence (Italy) by photosyntheticmicro-organisms was investigated. The greenmicroalga Coccomyxa was the first colonizer ofnewly restored marble surfaces, appearing one yearafter the periodic cleaning and restoration of thestatues. Two years after restoration this alga gaverise to very thin green biofilms, with densitiesreaching about 3 × 102 cells cm-2. Later,the biofilms were enriched by cyanobacterial forms,which became dominant. In about six years, aphotosynthetic microbial community, amounting to about3 × 104 cells cm-2, and structurally similarto that occurring on the unrestored statues wasdeveloped. This epilithic community showed amarked biodiversity; the main representative formsincluded Chroococcidiopsis, Leptolyngbya,Pleurocapsa, Coccomyxa and Apatococcus.Coccomyxa initiated the colonisation of themarble surfaces, favoured in this process by itsfacultative oligotrophic capacity and high cellsurface hydrophobicity, combined with tolerance ofhigh light intensity. The other investigated isolatedstrains did not show this set of features. Thesecretion of polysaccharidic substances and cellsurface hydrophobicity enhancing the capacity toadhere, favoured permanent colonisation of thecyanobacterial population. Indeed, the majority of thecyanobacterial strains (90%), were shown to besurrounded by exopolysaccharidic envelops, whichcontributed to the formation of stable microbialbiofilms, and possessed variable cell surfacehydrophobicity. 相似文献
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Strategies for the preparation of new fluorescent oligopeptide conjugates labeled with 4-ethoxymethylene-2-[1]-naphthyl-5(4H)-oxazolone (naOx-OEt) at the N-terminal on solid support or in solution have been devised. These procedures are simple and easy to carry out by reacting naOx-OEt or N(alpha)-naOx-amino acid with side chain protected peptide chains attached to resins. The integrity of the N-alkyl bond was maintained even after the trifluoracetic acid or HF based cleavages procedures. Our data show that the naOx fluorophore is compatible with both Fmoc/tBu and Boc/Bzl methods and also suggest that naOx-amino acid could be utilized as building blocks for solid phase peptide synthesis. Comparative analysis of fluorescence properties of naOx-conjugates indicated that the spectral properties of the fluorophore do not change after incorporating into peptides. The compact size, the definite chemical reaction for its introduction in combination with the appropriate spectral features (e.g., intense emission, pH independent fluorescent characteristics, and beneficial photobleaching dose constant and rates) and with chemical and spectral stability, naOx-based labeling could be attractive for novel cellular fluorescent techniques (e.g., in laser scanning confocal FRET) to study peptide-protein and protein-protein interactions even in biological matrices. 相似文献
14.
We utilize electrophoresis and find that a thermally treated equimolar mixture of the oligonucleotide d(G(5)T(5)) and its complementary oligonucleotide d(A(5)C(5)) exhibits either two bands or a single band in one lane, depending on the conditions of the incubation solutions. The thermally treated d(G(5)T(5)) solution loaded in a different lane exhibits a single band of the parallel quadruplex [d(G(5)T(5))](4), which is composed of homocyclic hydrogen-bonded G(4) and T(4) tetrads previously proposed. For the thermally treated equimolar mixture of d(G(5)T(5)) and d(A(5)C(5)), the fast band is assigned to a Watson-Crick d(G(5)T(5)). d(A(5)C(5)) duplex, so that the slow band with the same low mobility as that of [d(G(5)T(5))](4) may be assigned to either [d(G(5)T(5))](4) itself or a [d(G(5)T(5)). d(A(5)C(5))](2) quadruplex. If the latter compound is true, this may be the antiparallel quadruplex composed of the heterocyclic hydrogen-bonded G-C-G-C and T-A-T-A tetrads proposed previously. After removing these three bands for the duplex and two kinds of hypothetical quadruplexes, we electrophoretically elute the corresponding compounds in the same electrophoresis buffer using an electroeluter. The eluted compounds are ascertained to be stable by electrophoresis. The circular dichroism (CD) and UV absorption spectra measured for the three isolated compounds are found to be clearly different. For the electrophoretic elution of the hypothetical [d(G(5)T(5))](4) quadruplex, the result of the molecularity of n = 4 obtained from the CD melting curve analysis provides further support for the formation of the parallel [d(G(5)T(5))](4) quadruplex already proposed. For the thermally treated equimolar mixture of d(G(5)T(5)) and d(C(5)A(5)), the fast band with a molecularity of n = 2 corresponds to the Watson-Crick duplex, d(G(5)T(5)). d(A(5)C(5)). The slow band with a molecularity of n = 4 indicates the antiparallel quadruplex [d(G(5)T(5)). d(A(5)C(5))](2), whose observed CD and UV spectra are different from those of [d(G(5)T(5))](4). By electrophoresis, after reannealing the eluted compound [d(G(5)T(5)). d(A(5)C(5))](2), a distinct photograph showing the band splitting of this quadruplex band into the lower duplex and upper quadruplex bands is not possible; but by a transilluminator, we occasionally observe this band splitting with the naked eye. The linear response polarizability tensor calculations for the thus determined structures of the [d(G(5)T(5))](4) quadruplex, the McGavin-like [d(G(5)T(5)). d(A(5)C(5))](2) quadruplex, and the Watson-Crick d(G(5)T(5)). d(A(5)C(5)) duplex are found to qualitatively predict the observed CD and UV spectra. 相似文献
15.
Hasan Hosseinzadeh Saeid Nasrollanejad Zahra Dordiani Vahid Jamshidnezhad 《Archives Of Phytopathology And Plant Protection》2013,46(16):1879-1883
Sharka disease is one of the most damaging diseases of fruit trees in the world, which is caused by Plum pox virus (PPV) that belongs to the genus Potyvirus in the family Potyviridae. Each year, this virus decreases the yield and causes substantial economic damages to its host plants worldwide. This virus is quarantined in Iran but in recent years, suspicious symptoms of the disease were observed in different grown areas, such as Golestan province. During 2010, 420 samples with mosaic, chlorosis, necrosis, ring pattern, blotches, etc. symptoms were collected from the gardens in Golestan province that included 100 samples from plum, 100 from peach and 240 from nectarine. These samples were evaluated using a double-antibody sandwich-ELISA (DAS-ELISA) method and a polyclonal antibody. The results of this survey indicated that among the total of 420 samples, none of them showed positive reaction in DAS-ELISA test. 相似文献
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Stoschitzky K Koshucharova G Lercher P Maier R Sakotnik A Klein W Liebmann PM Lindner W 《Chirality》2001,13(7):342-346
Carvedilol is currently used as the racemic mixture, (R,S)-carvedilol, consisting of equal amounts of (R)-carvedilol, an alpha-blocker, and (S)-carvedilol, an alpha- and beta-blocker, which have never been tested in their optically pure forms in human subjects. We performed a randomized, double-blind, placebo-controlled, crossover study in 12 healthy male volunteers. Subjects received single oral doses of 25 mg (R,S)-carvedilol, 12.5 mg (R)-carvedilol, 12.5 mg (S)-carvedilol, and placebo at 8 AM as well as at 8 PM. Exercise was performed at 11 AM, and heart rate and blood pressure were measured at rest and after 10 min of exercise. Urine was collected between 10 AM and 6 PM, as well as between 10 PM and 6 AM, and the amounts of urinary 6-hydroxy-melatonin sulfate (aMT6s) were determined by RIA. Compared to placebo, (R)-carvedilol increased heart rate during exercise (+4%, P < 0.05) and recovery (+10%, P < 0.05); (S)-carvedilol decreased heart rate during exercise (-14%, P < 0.05) and recovery (-6%, P < 0.05), and systolic blood pressure during exercise (-12%, P < 0.05); (R,S)-carvedilol decreased heart rate during exercise (-11%, P < 0.05), and systolic blood pressure at rest (-7%, P < 0.05) and during exercise (-10%, P < 0.05). None of the agents had any significant effect on the release of aMT6s. Our results indicate that only (S)-carvedilol causes beta-blockade, whereas (R)-carvedilol appears to increase sympathetic tone, presumably as a physiological reaction to the decrease of blood pressure caused by alpha-blockade. None of the drugs had any influence on melatonin release. The weak clinical net effect of beta-blockade of (R,S)-carvedilol at rest might be one reason why this drug causes fewer side effects than other beta-blockers, such as a reduction of nocturnal melatonin release. 相似文献
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ROBERT C. VRIJENHOEK 《Molecular ecology》2010,19(20):4391-4411
Deep‐sea hydrothermal vents provide ephemeral habitats for animal communities that depend on chemosynthetic primary production. Sporadic volcanic and tectonic events destroy local vent fields and create new ones. Ongoing dispersal and cycles of extirpation and colonization affect the levels and distribution of genetic diversity in vent metapopulations. Several species exhibit evidence for stepping‐stone dispersal along relatively linear, oceanic, ridge axes. Other species exhibit very high rates of gene flow, although natural barriers associated with variation in depth, deep‐ocean currents, and lateral offsets of ridge axes often subdivide populations. Various degrees of impedance to dispersal across such boundaries are products of species‐specific life histories and behaviours. Though unrelated to the size of a species range, levels of genetic diversity appear to correspond with the number of active vent localities that a species occupies within its range. Pioneer species that rapidly colonize nascent vents tend to be less subdivided and more diverse genetically than species that are slow to establish colonies at vents. Understanding the diversity and connectivity of vent metapopulations provides essential information for designing deep‐sea preserves in regions that are under consideration for submarine mining of precious metals. 相似文献
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Katakura H Harada A Kataoka K Furusho M Tanaka F Wada H Ikenaka K 《The journal of gene medicine》2004,6(4):471-477
BACKGROUND: Although some cationic reagents, such as polybrene, improve gene transduction in vitro, their use in vivo is prohibited due to their toxicity to the exposed cells. This paper demonstrates that a new cationic reagent, poly(ethylene glycol)-poly(L-lysine) block copolymer (PEG-PLL), improves gene transduction with retroviral vectors without increasing cell toxicity. METHODS: A retroviral vector derived from the Moloney leukemia virus, containing the lacZ gene, was modified with PEG-PLL prior to transduction into NIH3T3, Lewis lung carcinoma, and primary cultured mouse brain cells. LacZ transduction efficacy was evaluated by counting the number of X-Gal-positive cells. RESULTS: We have demonstrated that PEG-PLL is able to stably modify the viral particle surface due to the affinity of the PEG moiety to the biomembrane, and neutralizes negative charges by the cationic nature of the poly-lysine residue. Thus, PEG-PLL increased the gene transduction efficiency and minimized cell toxicity because free PEG-PLL was removable by centrifugation. We have shown that PEG-PLL increased the viral gene transduction efficiency 3- to 7-fold with NIH3T3 or Lewis lung carcinoma cell lines without increasing cytotoxicity. It improved retroviral gene transduction efficacy even against labile cells, such as primary cultured brain cells. CONCLUSIONS: PEG-PLL is a novel reagent that improves retroviral gene transduction efficacy without increasing cytotoxicity. 相似文献
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Kankia BI 《Biopolymers》2004,74(3):232-239
A combination of ultrasound velocimetry, density, and UV spectroscopy has been employed to study the hydration effects of binding of Mn(2+) and alkaline-earth cations to poly(rA) and poly(rU) single strands. The hydration effects, obtained from volume and compressibility measurements, are positive due to overlapping the hydration shells of interacting molecules and consequently releasing the water molecules to bulk state. The volume effects of the binding to poly(rA), calculated per mole of cations, range from 30.6 to 40.6 cm(3) mol(-1) and the compressibility effects range from 59.2 x 10(-4) to 73.6 x 10(-4) cm(3) mol(-1) bar(-1). The volume and compressibility effects for poly(rU) are approximately 17 cm(3) mol(-1) and approximately 50 x 10(-4) cm(3) mol(-1) bar(-1), respectively. The comparative analysis of the dehydration effects suggests that the divalent cations bind to the polynucleotides in inner-sphere manner. In the case of poly(rU) the dehydration effects correspond to two direct coordination, probably between adjacent phosphate groups. The optical study did not reveal any effects of cation on the secondary structure or aggregation of poly(rU). In the case of single-helical poly(rA) binding is more specific: dehydration effects correspond to three to five direct contacts and must involve atomic groups of adenines, and the divalent cations stabilize and aggregate the polynucleotide. 相似文献
20.
Macroinvertebrate community in the lower Ebro river (NE Spain) 总被引:1,自引:1,他引:0
We examine the macroinvertebrate community composition and dynamics in the last 60 km of the Ebro river (NE Spain). Different sampling methods (individual stones, Surber, kick samplers and artificial substrate) were used depending on the characteristics of the sites chosen (substrate, current velocity, saline influence).The high nutrient content and the abundance of UFPOM is the origin of a high density in stones although no clear pattern exists between stone surface area and density or species richness. The high spatial heterogeneity and moderate disturbance intensity and frequency because of river regulation explains the relatively rich macroinvertebrate community and the low temporal changes in the community. 相似文献